Absorption and opacity threshold for a thin foil in a strong circularly polarized laser field.

We show that a commonly accepted transparency threshold for a thin foil in a strong circularly polarized normally incident laser pulse needs a refinement. We present an analytical model that correctly accounts for laser absorption. The refined threshold is determined not solely by the laser amplitude, but by other parameters that are equally or even more important. Our predictions are in perfect agreement with particle-in-cell simulations. The refined criterion is crucial for configuring laser plasma experiments in the high-field domain. In addition, an opaque foil steepens the pulse front, which can be important for numerous applications.

Improving the accuracy of simulation of radiation-reaction effects with implicit Runge-Kutta-Nyström methods.

The Landau-Lifshitz equation provides an efficient way to account for the effects of radiation reaction without acquiring the nonphysical solutions typical for the Lorentz-Abraham-Dirac equation. We solve the Landau-Lifshitz equation in its covariant four-vector form in order to control both the energy and momentum of radiating particles. Our study reveals that implicit time-symmetric collocation methods of the Runge-Kutta-Nyström type are superior in accuracy and better at maintaining the mass-shell condition than their explicit counterparts. We carry out an extensive study of numerical accuracy by comparing the analytical and numerical solutions of the Landau-Lifshitz equation. Finally, we present the results of the simulation of particle scattering by a focused laser pulse. Due to radiation reaction, particles are less capable of penetrating into the focal region compared to the case where radiation reaction is neglected. Our results are important for designing forthcoming experiments with high intensity laser fields.

Laser field absorption in self-generated electron-positron pair plasma.

Recently, much attention has been attracted to the problem of limitations on the attainable intensity of high power lasers [A. M. Fedotov et al., Phys. Rev. Lett. 105, 080402 (2010)]. The laser energy can be absorbed by electron-positron pair plasma produced from a seed by a strong laser field via the development of the electromagnetic cascades. The numerical model for a self-consistent study of electron-positron pair plasma dynamics is developed. Strong absorption of the laser energy in self-generated overdense electron-positron pair plasma is demonstrated. It is shown that the absorption becomes important for a not extremely high laser intensity I ∼ 10(24) W/cm(2) achievable in the near future.

Limitations on the attainable intensity of high power lasers.

It is shown that even a single e- e+ pair created by a superstrong laser field in vacuum would cause development of an avalanchelike QED cascade which rapidly depletes the incoming laser pulse. This confirms Bohr's old conjecture that the electric field of the critical QED strength E(S) = m2c3/eℏ could never be created.

Damping of electromagnetic waves due to electron-positron pair production.

The problem of the back reaction during the process of electron-positron pair production by a circularly polarized electromagnetic wave propagating in a plasma is investigated. A model based on the relativistic Boltzmann-Vlasov equation with a source term representing the Schwinger formula for the pair creation rate is used. The damping of the wave, the nonlinear up-shift of its frequency due to the plasma density increase, and the effect of the damping on the wave polarization and on the background plasma acceleration are investigated as a function of the wave amplitude.

[Possibility of major gene control over scale E of Cattel's test]. / O vozmozhnosti maior-gennogo kontrolia shkaly E testa Kattella.

The segregation analysis is made of inheritance of the E factor of the Cattell's 16PF Questionnaire on the basis of a population sample consisting of 108 free-structured pedigrees. The possibility of major gene control of inheritance for this quantitative trait is confirmed.

[Prognostic criterion in the mendelian analysis of quantitative traits]. / Prognosticheskii kriterii v mendelevskom analize kolichestvennykh priznakov.

Prediction test for estimation of genetical parameters and the fitness of the hypothesis is proposed. The test is based on coincidence of values of quantitative character in individuals predicted on the basis of the genetic analysis and the empirical measured values. The method gives a higher correctness of prediction of phenotypical values than statistical methods. The problem of a choice of the boundary values for the test is considered.